可逆性后部脑白质病.pptx

Posterior reversible encephalopathysyndrome (PRES)Posterior reversible encephalopathy syndrome (PRES) was first reported by Hinchey in 1996.1. It may occur due to a number of causes predominantly malignant hypertension, eclampsia, drugs such as tacrolimus, cyclosporine, autoimmune disease and patients undergoing organ transplant. After the timely and effective treatment of the clinical manifestation and neuroimaging changes can fully recover, neurological sequelae generally does not exist The most common clinical symptoms and signs are headache, altered alertness and behavior changes ranging from drowsiness to stupor, seizures, vomiting, mental abnormalities including confusion and abnormalities of visual perception. Seizures may begin focally but usually become generalized.Classically PRES ：characterized by hyperintensity on T2-weighted and FLAIR images bilaterally and symmetrically in the parieto – occipital regions which is caused by subcortical white matter vasogenic edema. Atypical PRES：other regions of the brain are involved except the parieto-occipital lobes .Includes brain stem, cerebellum, basal ganglia, and frontal lobes. Atypical imaging appearances include contrast enhancement , hemorrhage, unilaterality and restricteddiffusion on MRI and involvement of gray matter.Pathophysiology 1、The more popular theory suggests that hypertension leads to failure of autoregulation , subsequent hyperperfusion, and vasogenic edema.2、The other theory suggests that vasoconstriction and hypoperfusion leads to brain ischemia and subsequent vasogenic edema. The relative paucity of sympathetic innervations in the posterior brain results in increased susceptibility to hyperperfusion and vasogenic edema during acute blood pressure elevations. Most authorities believe that hypertensive encephalopathy and eclampsia share similar pathophysiologic mechanismsCase 1A 25-year old lady, primigravida；On the 3rd day of postpartum with sudden onset of giddiness, headache, vomiting, bilate